<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>BoxShadow</title>
    <style type="text/css">
        div {
            width: 800px;
            height: 300px;
            background: red;
            margin: 0 auto;
            box-shadow: 50px 30px 0px 0px yellow;
        }
    </style>
</head>
<body>
<div>大家好！欢迎来到慕课网！</div>
</body>
</html>